1. Field of the Invention
The present invention relates to monolithic capacitors and mounting structures of the monolithic capacitors. More specifically, the present invention relates to a monolithic capacitor that is used in a high-frequency circuit and to a mounting structure of the monolithic capacitor.
2. Description of the Related Art
As a decoupling capacitor that is used in a power supply circuit for an MPU (Micro Processing Unit) in a high frequency range on the order of several GHz, for example, a monolithic capacitor having a structure described in Japanese Unexamined Patent Application Publication No. 11-144996 (Patent Document 1) is known. In the monolithic capacitor, a plurality of terminals is provided such that adjacent terminals have opposite polarities. Thus, the length of paths of currents from positive terminals to negative terminals is relatively short, and currents flow in various ways. Furthermore, currents are caused to flow in opposite directions so that magnetic fluxes are canceled, thereby decreasing ESL (Equivalent Series Inductance).
However, in the monolithic capacitor described in Patent Document 1, ESR (Equivalent Series Resistance) also decreases as ESL decreases. Therefore, the problem of steep impedance characteristics arises.
As another example, according to Japanese Unexamined Patent Application Publication No. 2001-284170 (Patent Document 2), for each internal electrode that is provided in a main capacitor unit to define a capacitor, only one lead-out portion extends out to the outer surface of the main capacitor unit and is electrically connected to an external terminal electrode, thereby increasing ESR of the monolithic capacitor.
According to the structure described in Patent Document 2, however, although ESR is increased, ESL is also increased. This causes the problem of degradation of high-frequency characteristics.